The present invention relates to a developer replenishing apparatus used for a developing unit provided in an electrophotographic type image forming apparatus or the similar apparatus.
Conventionally, when developer (toner) is replenished to a developer reservoir section (a toner reservoir section), a delivery port of a developer storing container (a toner bottle or toner storing container) in which developer is stored, is mated with a replenishing port of the reservoir section, and the developer (toner) is replenished into the container at a stroke. However, phenomenon in which the developer scatters like as smoke, (emitting smoke phenomenon) occurs, and therefore, there is a possibility that the developer stains the periphery of the developer reservoir section.
Accordingly, recently, the following developer replenishing apparatus is used: a toner bottle is provided above the developer reservoir section so that the bottle can be rotated in the peripheral direction; by rotating the toner bottle in the peripheral direction, the developer is moved to one side by a rib of the inner peripheral surface corresponding to a spiral groove provided on the outer peripheral surface; and the developer can be gradually replenished from a delivery port provided on one side to the developer replenishing port.
In the developer reservoir section, a conveying screw to convey the replenished developer to the developing unit is provided, and further, a stirring member is also provided so as to level a hill of the developer replenished in the reservoir section and to make the replenished developer to be well mixed with the existing developer.
However, in the conventional apparatus, an operation to rotate the toner bottle in the peripheral direction and replenish the toner, is conducted singly, and the stirring member in the reservoir section is operated at a timing to operate a conveying screw to convey the replenished developer to the developing unit. Therefore, there is a problem in which the toner replenished from the toner bottle forms a hill in the reservoir section, thereby, an amount of toner is unstable.
Further, in the case where the stirring member is simultaneously operated when the toner bottle is rotated in the peripheral direction and the toner is replenished to the reservoir section, and in the case where the stirring member is not operated but only the conveying screw is singly operated when the developer in the reservoir section is conveyed to the developing unit, only toner around the conveying screw is moved, and toner still remains around that, which is disadvantageous.
Still further, when the operation in which the toner bottle is rotated in the peripheral direction and the toner is replenished to the reservoir, the operation of the stirring member, and the operation of the conveying screw in the reservoir section, are conducted simultaneously, the following problem occurs: when an amount of toner replenishment from the toner bottle to the reservoir section is not the same as an amount of toner conveyance to the developing unit by the conveying screw, the amount of toner in the reservoir section is gradually decreased, or overflows, and is unstable.
Yet further, it is considered that a driving source to rotate the toner bottle in the peripheral direction, a driving source of the stirring member, and a driving source of the conveying screw, are separately provided respectively, and the operation timing of them is controlled so that above problems do not occur even when these are independently operated. However, there is a problem that the production cost is increased when these driving sources are individually provided.
FIG. 8 is a sectional view showing a structure of the inside of the developer replenishing apparatus. In FIG. 8, the bottle-like toner storing container 5, which is extending vertically to the drawing, is supported by a container supporting section 21 of the developer replenishing apparatus 100 having a corresponding concave portion. A toner reservoir section 1 whose sectional view is approximately U-shaped, is formed below the container supporting section 21. Toner T replenished from the toner storing container 5 is piled in the toner reservoir section 1.
A sensor 124 to detect a remaining amount of toner T in the toner reservoir section 1 is located on the side surface of the toner reservoir section 1. The sensor 124 has a detecting surface 124a facing the inside of the toner reservoir section 1. Further, a plate-like stirring member 28 for stirring the toner T in the toner reservoir section 1, attached to a driving shaft 29 is located so as to be rotatable by the external driving power, at the center of the toner reservoir section 1. The stirring member 28 has also a function to clean the detecting surface 124a.
The sensor 124 is composed of a piezoelectric element, and can detect toner T contacting with its detecting surface. Accordingly, even when a piling level of the toner T is lower than the sensor 124, when only a small amount of toner T adheres to the detecting surface, the sensor 124 erroneously detects that an amount of toner T, which exceeds the level of the detecting surface, remains.
Therefore, the stirring member 28 to clean the detecting surface 124a of the sensor 124 is provided. That is, by rotating the driving shaft 29, the stirring member 28 is slidingly moved on the detecting surface. By such the sliding movement, the toner T adhered to the detecting surface 124a is removed, thereby, the detecting accuracy of the sensor 124 is increased.
However, by such the movement of the stirring member 28, a new problem occurs. The stirring member 28 is rotated in the direction of an arrow (clockwise) in FIG. 8 such that the stirring member 28 cleans the detecting surface 124a from below. Accordingly, the toner T adhered to the detecting surface 124 is cleaned by cleaning of stirring member 28, however, when toner T is removed by the rotating stirring member 28, there is a possibility that a cavity S of toner T is formed below the stirring member 28.
When such the cavity is formed, even if the remaining amount of toner T is enough, there is a possibility that the sensor 124 erroneously detects the toner T as if its remaining amount is lower than a predetermined level.
As a method to solve this problem, it is considered that a plurality of optical sensors are provided in the toner reservoir section, and the remaining amount of toner is collectively judged from the detected results. However, when a plurality of sensors are provided, cost of the toner replenishing apparatus, and further, the cost of an image forming apparatus is increased.
Furthermore, in the case of the toner bottle installation type developer replenishing apparatus, a member which is rotated together with the toner bottle is necessary, and only on a portion engaging with developer delivery port of the toner bottle of the rotating member, a seal member is provided.
Accordingly, it is necessary to make the member rotated with the toner bottle coincide with the surface on which the developer delivery port of the toner bottle is provided, therefore, there is a problem in which not only the adjustment is troublesome, but the member rotated with the toner bottle also exists, resulting in an increase of production cost.
Still further, because the delivery port of the toner storing container by the conventional technology is formed on a cylindrical surface, and the delivery port is sealed by a thin seal, generally it is difficult to peel the seal by a simple mechanism. Therefore, the operator is required to manually peel the seal directly before the toner storing container is set to the toner replenishing device. Accordingly, even when such the toner replenishing device is used, a possibility that hands are still stained, is not solved. In addition to that, there also be a request to use again the seal which has been peeled once, so as to seal the delivery port.